mcs/class/dlr/Runtime/Microsoft.Scripting.Core/Utils/Helpers.cs

   1
   2 /* ****************************************************************************
   3  *
   4  * Copyright (c) Microsoft Corporation.
   5  *
   6  * This source code is subject to terms and conditions of the Apache License, Version 2.0. A
   7  * copy of the license can be found in the License.html file at the root of this distribution. If
   8  * you cannot locate the  Apache License, Version 2.0, please send an email to
   9  * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound
  10  * by the terms of the Apache License, Version 2.0.
  11  *
  12  * You must not remove this notice, or any other, from this software.
  13  *
  14  *
  15  * ***************************************************************************/
  16
  17 #if !FEATURE_CORE_DLR
  18 using Microsoft.Scripting.Ast;
  19 using Microsoft.Scripting.Utils;
  20 #else
  21 using System.Linq.Expressions;
  22 #endif
  23
  24 using System.Collections.Generic;
  25
  26 namespace System.Dynamic.Utils {
  27     // Miscellaneous helpers that don't belong anywhere else
  28     internal static class Helpers {
  29
  30         internal static T CommonNode<T>(T first, T second, Func<T, T> parent) where T : class {
  31             var cmp = EqualityComparer<T>.Default;
  32             if (cmp.Equals(first, second)) {
  33                 return first;
  34             }
  35             var set = new Set<T>(cmp);
  36             for (T t = first; t != null; t = parent(t)) {
  37                 set.Add(t);
  38             }
  39             for (T t = second; t != null; t = parent(t)) {
  40                 if (set.Contains(t)) {
  41                     return t;
  42                 }
  43             }
  44             return null;
  45         }
  46
  47         internal static void IncrementCount<T>(T key, Dictionary<T, int> dict) {
  48             int count;
  49             dict.TryGetValue(key, out count);
  50             dict[key] = count + 1;
  51         }
  52     }
  53 }